CN211577390U

CN211577390U - Generator export PT early warning device that breaks wire

Info

Publication number: CN211577390U
Application number: CN201921957008.1U
Authority: CN
Inventors: 马中荣; 成玉峰
Original assignee: Jiuquan Iron and Steel Group Co Ltd
Current assignee: Jiuquan Iron and Steel Group Co Ltd
Priority date: 2019-11-13
Filing date: 2019-11-13
Publication date: 2020-09-25
Anticipated expiration: 2029-11-13

Abstract

The utility model discloses a generator export PT early warning device that breaks wire belongs to thermal power plant's electric power facility protection monitoring technology field, has solved the problem that the unable early warning in advance of pressure return circuit initial stage trouble. The utility model discloses a voltage transmitter and analog input module, voltage transmitter are equipped with 3 and connect respectively on three little buses of secondary of voltage transformer, and analog input module is including the voltage sampling module, pressure difference module, absolute value module, comparison module, three that connect gradually and get a module, delay module and alarm module, and voltage sampling module links to each other with voltage transmitter. The utility model discloses an analog input module carries out logic calculation, obtains early warning information, sends alarm signal, sends the early warning when the initial stage trouble appears in voltage circuit, reminds on duty and maintainer to inspect PT one, secondary circuit, prevents that the accident from expanding.

Description

Generator export PT early warning device that breaks wire

Technical Field

The utility model belongs to the technical field of thermal power plant's electric power facility protection monitoring, concretely relates to generator export PT early warning device that breaks.

Background

A generator outlet voltage transformer (PT) changes the primary voltage of 20KV at the outlet of the generator into secondary voltage of 100V, and supplies the secondary voltage to devices such as a generator-transformer group protection device, an excitation regulator, an electric energy meter and a power transmitter. When a voltage transformer is fused through primary fuse, faults such as poor contact of a primary loop and a secondary loop can cause inaccurate voltage acquisition, and results such as protection misoperation or failure, inaccurate electric energy metering and the like are caused. At present, a generator outlet voltage loop is mainly monitored by a PT (potential transformer) disconnection alarming function of a generator-transformer set protection device, the PT disconnection constant value is 8V, and the initial fault of the voltage loop cannot be effectively monitored.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a generator export PT early warning device that breaks wire to solve the unable problem of early warning in advance of voltage circuit initial stage trouble.

The technical scheme of the utility model is that: the utility model provides a generator export PT early warning device that breaks wire, includes voltage transmitter and analog input module, and voltage transmitter is equipped with 3 and connects respectively on voltage transformer's 3 little buses of secondary, and analog input module is including the voltage sampling module, pressure difference module, absolute value module, comparison module, three modules of getting, delay module and the alarm module that connect gradually, and voltage sampling module links to each other with voltage transmitter.

The utility model has the advantages that: the existing generator outlet PT disconnection monitoring function is generally realized by a generator microcomputer protection device, when PT disconnection faults occur, an alarm is given out and corresponding protection is locked, in order to prevent protection misoperation or refusal, a pressure difference alarm value is often set to be large, the method can only monitor faults such as complete fuse of a fuse, disconnection and the like, early warning cannot be carried out on initial faults such as slow fuse of the fuse, loosening of the connection and the like, and an operator on duty generally inspects the protection device once within 2 hours, cannot monitor voltage sampling in real time and confirms the operation condition of equipment. The utility model discloses an analog input module carries out a series of logic calculation, obtains early warning information, sends alarm signal, sends the early warning when the initial stage trouble appears in voltage circuit, reminds on duty and maintainer to inspect PT one, secondary circuit, prevents that the accident from expanding. The pressure difference early warning value can be set at any time, and is slightly larger than the maximum value by collecting the maximum value of the pressure difference during normal operation of the equipment within a period of time, so that the sensitivity of alarming can be ensured, the false alarming can be prevented, and the reliability is high. The utility model discloses simple structure, the practicality is strong.

Drawings

Fig. 1 is a schematic structural view of a generator outlet PT wire breakage early warning device of the present invention;

fig. 2 is a schematic structural diagram of an analog input module in the generator outlet PT disconnection warning device of the present invention;

fig. 3 is a flow chart of the work of the generator outlet PT wire breakage early warning device of the present invention;

fig. 4 is the utility model relates to a generator export PT disconnection early warning device's display effect picture.

In the figure, 1-voltage transformer; 2-a generator; 3-generator outlet bus; 4-secondary small bus; 5-a voltage transmitter; 6-analog input module; 7-a voltage sampling module; 8-a differential pressure module; 9-absolute value module; 10-a comparison module; 11-one module from three; 12-a delay module; 13-an alarm module; 14-display module.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings.

As shown in fig. 1 and 2, the generator outlet PT disconnection early warning device includes a voltage transmitter 5 and an analog input module 6, the voltage transmitter 5 is provided with 3 voltage transmitters and respectively connected to 3 secondary busbars 4 of a voltage transformer 1, the analog input module 6 includes a voltage sampling module 7, a differential pressure module 8, an absolute value module 9, a comparison module 10, a third-out-of-one module 11, a delay module 12 and an alarm module 13, which are sequentially connected, and the voltage sampling module 7 is connected with the voltage transmitter 5.

The analog input module 6 adopts DCS.

The voltage transformer 1 is connected to a generator outlet bus 3 of the generator 2.

The voltage sampling module 7, the voltage difference module 8 and the alarm module 13 are all connected with the display module 14.

The work flow of the utility model is shown in figure 3, and comprises the following steps:

s1, the voltage transmitters 5 respectively define the voltage data on the secondary small bus 4 as Uab, Ubc and Uca and send the voltage data to the voltage sampling module 7, and the voltage sampling module 7 sends the received data to the differential pressure module 8;

s2, the pressure difference module 8 calculates two differences among the three voltage data, namely delta U (ab-bc), delta U (bc-ca) and delta U (ca-ab), and sends the calculation results to the absolute value module 9, and the absolute value module 9 takes the absolute value of the received pressure difference data and sends the results to the comparison module 10;

s3, the comparison module 10 compares the received data with a preset differential pressure early warning value, and outputs an early warning signal to the one-out-of-three module 11 when the absolute value of the differential pressure exceeds the preset differential pressure early warning value;

s4, when the one-out-of-three module 11 receives any one pressure difference early warning signal, outputting a signal to the delay module 12, when the preset delay time is reached, outputting a signal to the alarm module 13 by the delay module 12, and sending an alarm by the alarm module 13; if the preset delay time is not reached, no alarm is given.

The display module 14 receives data information from the voltage sampling module 7, the voltage difference module 8 and the alarm module 13, and displays the voltage data, the voltage difference data and the alarm signal on a display, as shown in fig. 4. When the alarm condition is not reached, the display is grey, and when the alarm signal trigger is reached, the display is red. The utility model discloses with generator voltage and difference direct display on the display, operating personnel can look over at any time.

Claims

1. The utility model provides a generator export PT early warning device that breaks a line which characterized in that: including voltage transmitter (5) and analog input module (6), voltage transmitter (5) are equipped with 3 and connect respectively on three secondary minibus (4) of voltage transformer (1), and voltage transmitter (5) link to each other with analog input module (6), analog input module (6) are including voltage sampling module (7), pressure difference module (8), absolute value module (9), comparison module (10), three that connect gradually take one module (11), time delay module (12) and alarm module (13), voltage sampling module (7) link to each other with voltage transmitter (5).